Buttonhole-sewing machine



Nov. 3, 1925.

E. B. ALLEN BUTTONHOLE SEWING wmcnnm Filed July 23, 1921 10 Sheets-Sheet 1 INVENTOR WITNESSES:

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BUTTC NHOLE SEWING MACHINE Filed July 23. 1921 10 Sheets-Sheet 2 WITNESSES: MW em INVENTOR AM/3 m BY ATTORN EY 10 Sheets-She't 3 ATTORNEY Nov. 3, 1925.

E. B. ALLEN BUTTONHOLE sswme MACHINE Filed July 23, 1921 WITNESSES: W flew Nov. 3, 1925.

E. B. ALLEN sum'ounoma SEWING momma Filed July 23, 1921 10 Sheets-Sheet 4 INVENTOR ATTORNEY WITNESSES:

Nov. 3, 1925.

E. B. ALLEN BUTTONHOLE SEWING MACHINE Filed July 23. 1921 10 Sheets-Shet' 5 INVENTOR WITNESSES: W lid/AW f BY 4 TTORNEY Nov. 3, 1925.

WITNESSES:

aawq E. B. ALLEN BUTTONHOLE SEWING MACHINE Filed July 25, 1921 10 Sheets-Sheet 6 INVENTOR Nov. 3,1925. 1,559,539

E. B. ALLEN BUTTONHOLE SEWING MACHINE Filed July 23, 1921 10 Sheets-Shee't' '7 E: N INVENTOR WITNESSES:

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ATTORNEY E. B. ALLEN BUTTONHOLE SEWING MACHINE Nov. 3, 1925.

Fi1e Ju1y 2S, 1921 10 Sheets-Sheet 8 ATTORNEY Nov. 3, 1925. 1,559,539

E. B. ALLEN BUTTONHOLEZ SEWING MACHINE Filed July 23, 1921 10 Sheets-Sheet l0 INVENTOR I ATTORNE;

WITNESSES:

Patented Nov. 3, 1925.

UNITED STATES PATENT OFFICE.

EDWARD B. ALLEN, OF NEWTOWVN, CONNECTICUT, ASSIGNOR TO THE SINGER MANU- FACTURING COMPANY, OF ELIZABETH, NEW JERSEY. A CORPORATION OF NEW JERSEY.

BUTTONHOLE-SEWING MACHINE.

Application filed July 23,

To all whom it may concern:

Be it known that I, ED\VARD B. ALLEN, a citizen of the United States, residing at Newtown, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Buttonhole-Sewing Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

In studying the operation of machines of the automatic buttonhole sewingtype, it is customary to divide the various operations constituting a complete buttonhole producing cycle into three groups, viz: (1) operations performed preparatory to sewing; the sewing operation; and (3) operations performed subsequent to sewing. The operations included in group (1) may comprise, for example, the closing of the work-clamp, the tripping of the stop-motion device to start the stitchforming mechanism; and, if the machine is of the type which cuts the buttonhole before sewing, the cutting of the buttonhole preparatory to the tripping of the stop-motion device. Group (3) commonly includes such operations as the cuttin; of the sewing thread, the opening of the work-clamp. and, in machines of the type which cut the buttonhole after sewing the cutting of the buttonhole immediately succeeding the stitching. In machines of the eyelet-end type there is'also usually includ ed in group (3) the operation of reversely turning the stitch-forming mechanism to initial position. These various operations must of course, be performed in properly timed relation to one another. A

In the machine disclosed in my Patent No. 1,346,102, of July 13, 1920, I incorporated two auxiliary shafts. one stationary during the performance of the operations in groups (2) and (3) and making a single rotation preparatory to sewing to take care of the various operations falling in group (1). and the other stationary during the performance of the operations in groups (1) and (2) and making a single rotation sub sequent to sewing to take care of the various operations falling in group (3).

If the ever-pressing demand for increased production is to be met, a reduction in the time required for the machine to run through a complete buttonhole producing cycle must be effected. It does not appear 1921. Serial No. 487.001.

that the time required for the actual sewing operation can with practicability be decreased, since a speeding up of the sewing shaft would subject the stop-motion device and other parts to destructive shock. The present invention, therefore, has for an object the shortening of the time required for the machine to run through a complete cycle of operations, by reducing to a minimum the time required for the performance of the operations preparatory and subsequent to sewing.

Another object of the invention is to provide a machine of the class described with a simplified auxiliary mechanism for the performance of operations preparatory and subsequent to sewing, which mechanism will operate quietly, smoothly and with certainty, in the shortest possible time and without undue wear and tear on the arts.

Another object of the invention is to improve the straight buttonhole machine of the type represented, for example, in my Pat ent No. 885,310, of April 21, 1908. In operating a straight buttonhole machine of the type represented in the above patent, it, is necessary for the operator to manipulate two separate treadlcs, one of which serves to raise and lower the upper work-clamping foot and to pull off and sever the shuttle thread, and the other of which serves to trip the stop-motion device to start the stitch-forming mechanism. The present invention aims to provide an automatic straight buttonhole machine which will be more rapid in operation than prior straight buttonhole imachines, and the control of which will require a minimum of attention on the part of the operator.

Further objects of the invention are to improve and simplify various parts of the machine as hereinafter described and pointed out in the claims.

To the attainment of the ends in view, the invention is preferably embodied in a buttonhole machine of the straight type rep resented in my said Patent No. 885,310. It is tobe understood, however, that in its main aspect, the invention is not limited to any particular type of buttonhole machine but is useful in either straight or eyelet-end ma-' chine or, in fact. in automatic sewing machines of any of the usual types having accessory devices to be operated prior and subsequent to sewing. In the present machine the control of the operations prior and subsequent to sewing is centered in a single rotary element or shaft which is stationary during the sewing and Which is provided with automatic driving and stopping means for causing it to make a partial rotation with a continuous motion prior to sewing and another partial rotation with a continuous motion subsequent to sewing, the shaft being automatically stopped at the completion of each of said partial rotations. Preferably the auxiliary shaft makes, in the aggregate, only one complete rotation per buttonhole producing cycle, such rotation being made in two stages, the first stage or partial rotation being made prior to sewing and the second stage or partial rotation being made subsequent to sewing.

A further object of the invention is to provide the auxiliary rotary element with an improved form of driving and stopping means whereby it is caused at each actuation thereof to quickly make a partial rotation with a continuousmotion and then come to rest. Such means may comprise a continuously running driving element and a driven element with a clutch connection between them, said connection being controlled by a plurality of clutch operating dogs mounted upon and slidable radially of the driven element in angularly spaced relation andinterconnected so as to partake simultaneously of inward or outward radial movements. These dogs are adapted to cooperate successively with a clutch-controllin lever mounted on the frame of the machlne and controlled by a finger release and by a connection with the stop-motion device for the stitch-forming mechanism. I

When the finger release is depressed, the auxiliary shaft is tripped into action and makes a partial rotation during which it operates through suitable connections to automatically perform the desired operations preparatory to sewing, such as the closing of the work-clamp and the tripping of the stop-motion to start the stitch-forming mechanism. After the buttonhole'is stitched the stop-motion in acting to stop the stitchforming mechanism, automatically trips the auxiliary shaft into action and such shaft makes a second partial rotation during which it automatically performs the desired operations subsequent to sewing, such as the cutting of the buttonhole, the c'uttlng of the sewing threads, the opening of the workclamp to release the work, etc.

In the accompanying drawings, Fig. 1 is a right side elevation, partly in section. of a machine embodying the invention. Fig. 2 is a left side elevation, partly in section, of the machine. Figs. 3 and 4 are, respectively, front and rear end elevations of the machine. Fig. 5 is a section on the line 55,

aeeasee Fig. 3. Fig. 6 is a horizontal section through the bracketarm of the-machine at a'level above the bed and showing the latter in plan. Fig. 7 is a section on the line 77, Fig.6. Fig. 8 is a plan view of the work- 'clamp supporting plate shown in Fig. 6 showing its connection with the feed-wheel. Fig. 9 is a bottom plan view of the machine.

Fig. 10 is a section on the line 1010, Fig. 9. Fig. 11 is a side elevation, partly in section, of the clamp-opening and -closing mechanism. Fig. 12 is a top' plan view of the bracket-arm and parts carried thereby. Fig. 13 is a section on line 13-13, Fig. 12. Fig. 14 is a horizontal section on the line let-14, Fig. 1. Fig. 15 is a section on the line 1515, Fig. 1. Fig. 16 is a transverse vertical section through the bed and bracket-arm of the machine, showing the transversely disposed auxiliary rotary element or shaft. Fig. 17 is a detail view of the finger release lever and the locking means therefor. Fig. 18 is a detail view of the stop-motion cam and plunger. Fig. 19 is a view illustrating the motion of the lower end of the stop-motion plunger as the latter swings to stopping position.

Fig. 20 is a plan view of the needle-thread tension device and the release therefor. Fig. 21 is a detail view showing the inner face of the driven clutch-disc and clutch-controt ling lever for the auxiliary shaft.

Figs.

22 and 23 are detail views of the clutch mechanism for the auxiliary shaft. Fig.

24 is a section .on the line 2 1-24, Fig. 21.

of the clutch-lever operating latch when the finger-release is operated to start the ma' chine on its cycle of operations. Fig. 31

is a similar view'showing the movement of said latch under the influence of a cam on the driven clutch-disc during its partial rotation prior to sewing. Fig. 32 is a detail view illustrating the actuation of said latch by a bellcra'nk lever which is connected to the stop-motion to initiate the second partial rotation ofthe auxiliary shaft or the partial rotation subsequent to sewing. Fig. 33 is a view similar to Fig. 31, illustrating the movement of the clutch controlling latch under the influence of a second cam on the driven clutch-disc during its second partial rotation. Fig. 34 is a detail view. in plan, of the clutch controlling lever and its operating latch, showing its movement under the influence of the finger release, as

in Fig. 30. Fig. 35 is a similar view showing the movement of the clutch controlling lever under the influence of the stop-motion at the completion of the sewing, as in Fig. 32. Fig. 36 1s a detail elevation illustrating the movement of the parts of the needlethreadcutter carried by the work-clamp during the sewing of the first side of the buttonhole. Fig. 37 is a similar view showing the motion of the needle-thread-cutter operating means at the completion of the sewing operation, and Fig. 37' is a fragmentar plan view of the work-clamping foot an thread-cutting and nipping blade in the position shown in Fig. 37.

In the specific embodiment of the invention illustrated, the machine is of the straight buttonhole type represented in my said Patent No. 885,310. Such a machine commonly comprises a hollow rectangular bed 1 from the rear end of which rises the standard 2 of the bracket arm 3 terminating in the head 4. A reciprocating and laterally vibrating needle-bar 5 carrying the eyepointed needle 6 is journaled in the usual swinging gate 7 which is mounted on the pivot pins 8, 9 and derives its vibratory movement from a needle-jogging camgroove 10, Fig. 12, in the cam-wheel 11 which is mounted upon the screw-pin 12,

Fig. 2, supported by a transverse brace 13, Fig. 14, cast within the bracket-arm The cam-groove receives the follower roll 14, Fig. 12, on one.arm 15 of a bellcrank-lever fulcrumed at 16 on thebrace 13. The other arm 17 of the bellcrank-lever isslotted at 18 to adjustably receive the pin 19 at the rear end of the link 20, the front end of which is connected at 21 to a lateral arm 22 on the needle-gate 7.

The cam-wheel 11 is in the form of a bevel gear which meshes with the gear 28 on the main or sewing shaft 24 journaled within and longitudinally of the bracket-arm 3; the

ratio of gearing being such that the shaft 24 makes two rotations to one rotation of the Wheel 11.

The needle-bar 5 is reciprocated by means of the usual link connection 25 with the crank-pin 26 carried by an arm 27 rigid with the usual take-up operating crank-pin 28 fixed to the crank-arm 29 on the front end of the sewing shaft. 24.

In the machine illustrated, the needle cooperates with the usual shuttle 30 within the bed 1, such shuttle being mounted in the race 31 and oscillated by means of the shaft 32 having the usual driving connections with the crank 33 on the sewing shaft; such connections including the crank-arm 34, slotted rock-lever 35 pivoted at 36, and the pitman 37.

The Work-holder comprises a supporting plate 38, Fig. 8, upon which is secured by the screws 39, the lateral extension plate 40,

upon which is adjustably mounted between the guide blocks 41, by means of the screws 42, the supporting base 43, see also Fig. 11, for the upper clamping foot 44. The base 43 is formed with slots 45 for the screws 42, which slots are parallel to the guide blocks 41 and permit the base 43 to be adjusted forwardly or rearwardly on the extension plate 40 to secure registry of the clamping foot and the stitched pattern. The plate 40 is also provided with additional holes 46 for the screws 42, thus increasing the range of adjustment.

The base-plate 43 is formed with spaced upstanding ears 47 fixedly supporting the horizontal pii'ot-pin 48 for the forward section 49 of the upper work-clamping lever, the rearward section 50 of which is pivotally mounted on the pin 48 independently of the forward section 49. By referring to Figs. 7 and 11, it will be observed that the rearward end of the forward section 49 of the work-clamping lever has secured thereto by screws 51, 51 a plate 52 formed with depending ears 53 embracing the ears 47 and.

apertured to receive and rock upon the pivotpin 48. The clamp-lever section 49 is bifurcated, as shown in Fig. 6, to form two forwardly directed resilient arms which are loosely connected at their free ends to the upper clamping foot 44, such foot being preferably of the usual construction disclosed in my said Patent No. 885,310. The rearward section 50 of the work-clamping lever is secured by screws 54 to a yoke 55 including the spaced depending arms 56 apertured to fit and rock upon the pivot-pin 48 independently of the forward clamp-lever section 49.

The sections 49 and 50 of the workclamping lever may be coupled together to move as a one piece lever, by means of the pin 57 which at its lower end is screwed into an aperture in the plate 52, and carries the lock nut 58. This pin projects upwardly through a clearance slot 59 in the forward end of the lever section 50 and at its upper end is formed with a head 60, Fig. 11, in which is fixed the lateral screw-pin 61 supporting the cam-lever 62. The cam-lever 62 is adapted to bear upon the wear-plate 63 secured to the forward end of the leversection 50 and bridging the clearance slot 59, (see Fig. 6). The cam-lever 62 includes a handle 62 which, when turned horizon-. tally, Figs. 7 and 11, effectively locks the two sections of the clamp-lever together. The forward section 49 of the clamplever is under a constant downward pres sure effected by the spring 64 surounding the post 65 rigidly secured to the base 43, and at its lower end bearing upon the plate-like flange 66 at the lower end of the sleeve 67 slidable on the post 65 and carrying the pressure heads 68 which bear upon the arms of the clamping-lever section 49. The pressure of the spring 64 is regulated by means of the thumb-nut 69.

The work-holder supporting plate 38 is mounted to slide longitudinally in suitable ways in the usual transverse slide-plate which is shifted crosswise of the bed 1 by the usual means including the lever 71, Fig. 9, pivotally connected at 71 to the slideplate 70 and slidably pivoted at 72 to the bed 1. The lever 71 carries a cam-roll 73 entering the usual cam-slot 74 in the upper face of a feed-wheel 75 of the well known type used, for example, in Singer No. 71-10 machines. This feed-wheel is secured to the lower end of the vertical feed-shaft 7 6. The longitudinal movement of the work-holder is effected by the usual cam-slot 77 which is entered by a follower-roll on one arm 78 of a bellcrank-lever fulcrumed at 79 within the bed 1. The other arm 80 of the bellcranklever is slotted to adjustably receive a pin 81 at one end of a link 82 the other end of which is connected to the block 83, Figs. 8, 9 and 10, which is mounted to slide longitudinall of the bed 1 and is formed with an extens1on84 fitting the transverse slot 85 in the plate 38.

The vertical feed-shaft 76 is journaled in the bearings 86, 87, in the arm 3 and bed 1, respectively, Fig. 16, and has fixed thereto adjacent its upper end, the gear wheel 88 which meshes with the pinion 89 fixed to the gear 90 journaled on the bearing pin 91 fixed to the outer end of the radius arm 92 the inner apertured end of which embraces and may turn relative to the feed-shaft 76.

The gear 90, Figs. 1 and 13, meshes with the pinion 93 secured to the lower end of the shaft 94 journaled in the long bearing sleeve 95 let into the side of the bracketarm 3, Fig. 14, and secured in position by screws 96 passing through lateral ears 97 projecting oppositely from the sleeve 95. The sleeve 95 is formed with a lateral extension 98, Figs. 15 and 16, having a vertical aperture in which is freely fitted a cylindrical piece 99 apertured horizontally to receive the anchor-rod 100 one end of which is enlarged and apertured to embrace the upward extension 101 of the bearing pin 91. The extension 98 is also provided with a clearance aperture 102 for the anchor-rod 100. A set-screw 103 serves to fix the anchorrod 100 to the cylindrical piece 99.

Fixed to the upper end of the shaft 94, Figs. 12 and 13, is the star-wheel 104 which is driven by the diametrically opposed pins 105, projecting upwardly from the cylindrical block 106 secured upon and coaxially with the cam-wheel 11, as shown in Fig. 2. By means of the described connections the feed-wheel is given a. positive step-by-step motion without danger of overthrow; the periods of dwell occurring while the needle is in the work. The number of stitches in the buttonhole may be altered by substitutng for the gears 89, 90, similar gears hav- 111 different numbers of teeth.

The machine illustrated is provided with an auxiliary rotary control element or shaft 107, Figs. 6 and 16, which is journaled transversely of the bed 1 in pillow blocks 108, 109 secured to the latter. Pinned to the shaft 107 at 110', Fig. 24 is the cylindrical hub 110 of the driven-clutch disc 111 which is formed with a pair of radial slideways 112, 113, Fig. 22, spaced angularly about 120 and adapted to receive the slideblocks 114 and 115, respectively. The inner end of the slide-block 114, Figs. 22 and 26 is reduced in thickness and formed with a cylindrical stud 114 which enters an aper- .ture in one end of a link 116 the opposite apertured end of which embraces a similar 85 stud 117 at the free end of one arm 11% of a bellcrank-lever fulcrumed at 119 within a recess 120 in the outer face of the driven disc 111. The other arm 121 of the bellcrank-lever is formed with a circular extremity 122 which is received in the transverse slot 123 in the inner end of the slideblock 115. The slide-blocks 114 and are thus interconnected so that they will move simultaneously either inwardly or outwardly. A spring 124 secured by a screw 125 within a recess 126 in the outer face of the disc 111 bears against the inner end of the slide-block 115 and tends to force the latter and its companion block 114 outwardly. 1 The slide-block 114 is formed with a lateral lug 127 which extends through the slot 128, Fig. 21, in a cam-plate 129 let into the inner face of the disc 111. The outer end of this slot limits the radial movement of the slide- 1 5 blocks under the influence of the spring 124. The slide-block 115 is formed with a lateral lug 130 similar to the lug 127. The lugs 127, 130 extend inwardly beyond the plane of the inner face of the driven clutch disc and are 110 adapted to coact successively with a clutch controlling lever to be described. The plate 129 is formed with a cam-edge 129, projecting beyond the periphery of the disc 111, and another similar cam-plate 131 having a 115 cam edge 132 is let into the disc 111 at a position spaced in advance of the position of the cam-plate 129, a distance corresponding to that between the slideways 112, 113.

Mounted on the outer face of the driven clutch disc 111, i. e., the face shown in Fig. 22, by screws 133, is the ring 134, Figs. 1, 23 and 30. The inner face of the ring 134, or the face shown in Fig. 23, is in contact relation with the outer face of the disc 111, and is recessed at 135 to receive the three clutch-roll operating levers 136 which are fulcrumed on the pins 137 carried by the ring 134. The ring 134 is peripherally notched to receive the clutch-rolls 138, Fig.

23, and to provide the end walls 139 and the inclined walls 140 along which the clutch rolls are urged by the coilsprings 141 housed in suitable apertures in the end-walls 139 of the clutch roll notches. The levers 136 which serve to force the clutch rolls 138 down the inclined walls 140 and toward the end walls 139 are formed with tail pieces 142 which are acted upon by the camdisc 143 mounted to turn upon and relatively to the auxiliary shaft 107. The camdisc 143 is formed with peripheral depressions 144 and elevations 145 against which the tail pieces 142 of the levers 136 rest. The camdisc 143 is also slotted radially at 146 to receive the roll 147 carried by the link 116.

Mounted to rotate constantly on the outer end of the auxiliary shaft 107 is the driving pulley 148 formed with the belt groove 149 and an inwardly extending flange 150 which fits over the ring 134 and affords a cylindrical inner clutch wall 151. lVhen either of the slide blocks 114, 115 is forced inwardly against the pressure of the spring 124, the cam ring 143 is turned clockwise, Fig. 23 by the roll 147 on the link 116 and the cam elevations 145 operate upon the levers 136 to cause them to force the clutch rolls 138 toward the end walls 139 and out of wedging engagement with the cylindrical driving wall 151 and the inclined driven walls 140. When the slide-blocks are per mitted to move outwardly under the influence of the spring 124, the cam disc 143 is rotated counter-clockwise. Fig. 23, and the clutch rolls 138 are permitted to move under the influence of the springs 141 into wedging engagement with the driving wall 151 and inclined driven walls 140.

The radial movements of the slide-blocks 114, 115 to clutch and deelutch the driving and driven wheels. 148 and 111, respectively, are c'ontrolled by the clutch-controlling lever 152 of a form common in this art and shown. for example, in my Patent No. 1,048.786, of December 31. 1912. This lever is fulcrumed on the vertical pin 153 rising from the bed 1 and is formed at its forward end with a plate-like head 154 having in its i'ace adjacent the driven disc 111 a recess 155, Fig. 1, in which is pivoted the usual latchplate 156. The head 154 is also formed with the usual camedge 157 at the lower end of which is the stop-shoulder 158. lVhen the clinch-controlling ]ever 152 is in the position shown in Figs. 1 and 21, the slide-block 114 and its companion 115 are held in their inner or declutching positions by the lower end of the cam edge 157 which is engaged by the lug 127. Vhen the lever 152 is shifted away from the disc 111, as indicated in Fig. 34, the slide-blocks are released and permitted to move outwardly to clutch the auxiliary shaft 107 to the constantly rotating pulley 148. When the lever 152 is shift-- ed toward the disc 111, the cam-edge 157 is carried into the path of circular movement of the lugs 127, 130 on the slideblocks and when engaged by one of these lugs will force such lug inwardly and declutch the driving and driven discs. When such lug strikes'the shoulder 158, the auxiliary shaft 107 will be stopped and a rebound of such shaft will be prevented by the movement of the lower end of the latch 156, Fig. 21, into position over said lug under the influence of the spring 159.

The hub of the driven disc 111 is formed with a cam-groove 160 which is entered by a pin 161 depending from the clutchcontrolling lever 152 This cam-slot is formed at its two stopping positions relative to the pin 161, with otfsets 162, see Fig. 29, which permit the lever 152 to be shifted away from the disc 111 to start the auxiliary shaft 107. Immediately after one of the slide-blocks has been released and the auxiliary shaft started, one of the inclined portions 163 of the cam-slot 160 engages the pin 161 and returns the head 154 of the clutch-controlling lever to stopping position before the other slide-block has reached the declutching cam-edge 157. The shaft 107 will therefore invariably be stopped after executing a partial rotation; the first partiai rotation being preferably about 120 and the other about 240.

The first partial rotation .of-the auxiliary shaft, or the partial rotation of say 120 preparatory to sewing, is initiated by the operator in depressing the finger lever 164, Figs. 2 and 6, pivoted at 165 on a bracket 166 mounted on the bed 1. A spring 167 tends to restore the finger lever to initial position after it has been depressed. The rearward end of the finger lever extends under the horizontal arm 168, Fig. 16, of a bellcrank-lever fulcrumed at 169 on the bearing block 108. The upright arm 170 of the bellcrank-lever is connected by the link 171 to the clutch-controlling lever 152. Pressure upon the front end of the finger lever 164 thus pulls the clutch-controlling lever away from the driven disc 111 and releases the slide-block 114 to start the auxiliary shaft. The spring 172 anchored at its opposite ends to the arm 17 0 and bed 1, respectively, tends to restore the lever 152 to stopping position.

The sewing shaft 24 is equipped with the usual startand stop-motion device such as disclosed in my said Patent No. 885,310. Mounted on the sewing shaft are the tight and loose pulleys 173, 174, respectively, to the former of which is fixed the stopping cam 175 with which coacts the usual stopping plunger 176 carried by the stop-motion lever.177 fulcrumed at 178 on the bracket 179. \Vhen the lever 177 occupies its vertical or full-line position, Fig. 1, the sewing Gil shaft is locked by the plunger 176, the upper end of which enters the stop-notch 180 in the cam 175 at which time the belt shipper 181 holds the belt on the loose pulley 174. hen the lever 177 is swung to starting or dotted line position, Fig. 1, against the force of the spring 182, the plunger 176 is shifted laterally out of the stop-notch 180 and the belt is shifted onto the tight pulley 173. \Vhen the lever 177 is released, the spring 182 forces it; to full line position, Fig. l, and the plunger 176 is first engaged and forced downwardly b the cam-rise 183, Fig. 18, after which the p unger is projected upwardly by its spring 184 into the stop-notch 180; this action being common to stop-motion devices of the present character. The stop-motion lever 177 is held in running or dotted line position, Fig. 2, by means of a spring-pressed latch-lever 185, Fig. 9, which enters a notch 186 in the rod 187 depending from the front end of the arm 188 rigid with the st0pmotion lever 17 7 In my prior machine equipped with this stop-motion device. a treadle was connected to the rod 187 to tilt the stop-motion lever 177 to running position to start the stitchforming mechanism. In the present machine. such lever is automatically tilted to starting position by a connection with the auxiliary shaft 107. Referring to Figs. 1 and 11, it will be observed that the shaft 107 has mounted thereon a stop-motion actuating cam 189 which is engaged by the follower roll 190 mounted on the lever 191 fulcrumed at 192 on the bracket 193 secured to the side of the standard 2. The lever 191, is connected at 194 to one end of a link 1% the opposite end of which is connected at 196 to the stop-motion lever 177'. During the first partial rotation of the shaft 107, the cam 189 turns from full to dotted line position, Fig. 11, and swings the stop-motion lever from full to dotted line position, Fig. 1, thereby starting the stitch-forming mechanism; the lever 177 being retained in running position by the spring-pressed latchlever 185 until the sewing is completed. When the sewing is completed, the tripping point 197, Fig. 9. on the feed-wheel engages a. complementary point 198 adjustably mounted on the latch-lever 185 and withdraws the latter from the notch 186, thus rcleasing the stopmiotion lever 177 which is swung to stopping or full line position, Fig. 2, by the spring 182.

It will be remembered that when the stopmotion 'device operates to stop the sewing shaft. the plunger 176 is first engaged and forced downwardly by the cam-rise 183 on the st vpping cam 175, after which the plungcr is projected upwardly by its spring 184 into the stop-notch 180. This vertical reciprocatory motion of the stop-motion plunger is utilized to shift the clutch-controlling lever 152 to start the auxiliary shaft 107 on its partial rotation subsequent to sewing.

The clutch-controlling lever 152 includes a rearwardly extending arm 199 having a transversely extending horizontal bearing aperture for the fulcrum pin 200 to the inner end of which is fixed the extension arm 201. Fixed to the outer end of the pin 200 is the forwardly extending lever-arm 202, the end 203 of which extends into the circular path of movement of the cams 129 and 132 on thedriven clutch-disc 111. A spring 204 secured to the arm 199 and pressing downwardly on the extension arm 201 tends to maintain the latter arm in a horizontal position with the end of the lever arm 202 in contact with the circular peripheral portion of the disc 111, as shown in dotted lines in Fig. 30.

Mounted in bearings 205 within the bed 1 is a shaft 206 to which is fixed an upright arm 207 the free'end of which extends through an aperture 208 in the bed 1 and terminates adjacent the rearward extremity of the pivoted extension arm 201 of the clutch controlling lever 152. Also fixed to the shaft 206 is the horizontal arm 209 the free end of which is formed with a socketed boss 210. Fig. 2, for reception of the springprcssed latch-pin 211 which coacts with the ifting shoulder 212 formed in the lower end-portion of the stop-motion plunger 176. A spring 213 connected at its opposite ends to the arm 207 and bed 1, respectively, tends to hold the arms 209 and 207 in the positions shown in Fig. 32.

\Vhen the machine is sewing, the stop motion plunger and latch-pin 211 occupy the relative positions shown in dotted lines in Fig. 19, and the arm 207 and extension arm 201 occupy the relative positions shown in full lines in Fig. 32. When the stopinotion lever 17 7 is released at the end of the sewing operation by the action of the tripping point 197 on the latch-lever 185, the stop-motion plunger 176 is first carried from dotted to full line position, Figs. 2 and 19 and pushes the latch-pin 211 endwise into its socket 210. As the plunger 176 is depressed by the cam-rise 183 on the stopping cam 175. the lifting shoulder 212 is depressed below th level of the latch-pin 211 which thereupon is projected into position above the shoulder 212 and is lifted by such shoulder to the position shown in dotted lines in Fig. 32 as the plunger 176 is projected upwardly into the stop-notch 180.

The lifting of the latch-pin 211 rocks the shaft 206 and shifts the arm 207 from full to dotted line position, Fig. 32, during which movement the upper end of such arm en gages the lever extension 201 and shifts it to the left, sufliciently to rock the'clutchcontrolling lever 152 to starting position, as shown in dotted lines, Fig. 35, thereby initiating the second partial rotation of the auxiliary shaft 107.

The raising and lowering of the clamping foot 44 is automatically controlled by a cam 214 fixed to the auxiliary shaft 107. YVhen the machine is at rest. the cam 214, Fig. 11, acting on the rearward end of the clamping lever extension 50 holds the forward section 49 of the clamping lever elevated against the pressure of the spring 64. \Vhen the auxiliary shaft makes its first partial rotation, the cam 214 turns from full to dotted line position, Fig. 11, and permits the spring 67 to press the clamping foot 44 upon the Work introduced beneath the latter. After the sewing is completed the second partial rotation of the shaft 107 causes the cam 214 to turn from dotted to full line position, thereby elevating the clamping foot 44. In this connection it may be observed that the operator may lower the clamping foot prior to starting the machine, by swinging the handle 62' of the lifting cam 62 from horizontal to vertical position as shown in Fig. 1. This provision is useful whenever it is desired to locate a particular space on the work precisely in sewing position, as in repairing or restitching a previously cut and stitched buttonhole. After the work-holder is thus closed manually and the machine started the operator may swing the lever 62' to its horizontal position during the sewing and thus couple together the clamp-lever sections, thereby providing for the automatic opening of the work-clamp at the completion of the buttonhole. If it is desired to cut th buttonhole without releasing it, the operator may uncouple the clamp-lever sections during the sewing by swinging the lever 62 to vertical position.

The machine is equipped with a buttonhole cutter which is operated by a connection with the auxiliary shaft 107. When, as in the present instance, the invention is embodied in a straight buttonhole machine, it is preferred to use a cutting blade 215 of the type which operates after the buttonhole is stitched and has an inclined and sharpened knife edge 216 which is projected through the usual slit 217 in the throat-plate. Heretofore, as illustrated for example in my Patout No. 743.213. of November 3, 1903, the knife 215 was operated by a connection with the stop-motion plunger. In the present instance the usual cutter-bar 217 to the lower end of which is fixed the knife-carrying bracket 218 is connected by the link 219 to the cutter-lever 220 fulcrumed at 221 to the bracket-arm '3. The rearward end of the cutter-lever 220 is connected by the pitman 222 to the crank 223 on the auxiliary shaft 107. The relative angular relationship of the crank 223 and the clutch controlling slide-blocks 114 and 115 is such that during the first partial rotation of the shaft 107 the crank 223 is turned approximately 120 in the direction of the arrow from the position a to the position b, Fig. 2, thus giving to the knife 215 a slight up-and-down .idle movement. During the second partial rotation of the auxiliary shaft. however, the crank 223 is turned about 240 from the position b to the position a and imparts a cutting impulse to the knife 215, projecting the latter into the slot 217 in the throat-plate and withdrawing it therefrom. This crank motion affords a positive. efficient and quiet cutteroperating means.

The needle-thread may be cut bv means of a thread-cutting and -nipping blade 224, Figs. 6 and 11, of the usual construction disclosed in my said Patent No. 885,310. Such a thread-cutting blade is fulcrumed as at 225 on the clamping foot 44 and is operated by a crank-arm 226 to which is connected the forward end of a rod 227 the rearward end of which is slidably received by an apertured car 228 of a bracket 229 which may be secured beneath the screws 54 on the rear clamp-lever-section 50. The usual spring 230 connected at one end to a collar 231 on the rod 227 and at its other end to the ear 228 tends to pull the rod 227 toward the rear of the machine and thus impart a cutting impulse to the blade 224.

Fulcrumed on the standard 2 at 232, Fig. 2, is a lever 232 which is adiustable in length; being made in two sections joined by the usual screw and slot connections 233. The forward end of this lever is extended laterally to form a stop 234 for the rearward end of the rod 227. The lever 232 is formed with a downward extension 235 which rests upon a cam 236 fixed to the auxiliary shaft 107. A spring 232" holds the lever 232 in cooperative relation with the cam 236.

When the machine sews down the first side of the buttonhole the work-holder and thread-cutter parts carried therebV move from full to dotted line position, Fig. 36; the rearward end of the rod 227 passing under and liftingthe forward end of the lever 232 which is restored to initial position by the spring 232". As the sewing proceeds along the return side of the buttonhole the rod 227 is carried into engagement with and detained by the end 234 of the lever 232. while the pivot for the cutter-blade 224 continues its travel with the clamp-foot 44. This action causes the compound nipper and cutter-blade 224 to be slowly retracted from the position shown in Fig. 6 to a position at the other side of the needle-throat. When the stitch-forming mechanism is stopped the cutting and nipping blade 224 and associated parts occupy the positions shown in full lines in Figs. 37 and 37. As the auxiliary shaft 107 executes its second partial rotation, the cam 236 lifts the lever 232 and thereby releases the rod 227 which is suddenly shifted to dotted line position, Fig. 37, to cut and nip the needle-thread.

The shuttle thread may also be pulled off and severed by a connection with the auxiliary shaft 107. In Fig. 9 is illustrated the usual shuttle thread pull-off lever 237 which is pivoted at 238 to a plate 239 fixed to the bed 1 and is formed with a slot 240 which is entered by a screw 241 threaded into the usual slide-bar 242. Shuttle threadcutters of this type, as illustrated in my said Patent No. 885,310, commonly employ a cuttingblade 243 which is carried by the slide-bar 242 and cooperates with a stationary blade 244 below the throat-plate. In the present instance the slide-bar receives an endwise impulse during the second partial rotation of the auxiliary shaft, through a lever 245 which is fulcrumed at 246. The forward end of this lever is forked to embrace the pin 247 on the slide-bar 242. while the rearward end of such lever carries a camroll 248 which is held in engagement with the lateral face cam 249 on the hub 110 of the driven disc 111 by the spring 250. During the first partial rotation of the auxiliary shaft the cam 249 has no action upon the lever 245. During the second partial rotation of the auxiliary shaft, however, the cam 249 imparts an operative reciprocatory impulse to the slide-bar 242, thereby effecting a pulling off and severance of the shuttle thread.

The machine may be provided with a needle-thread tension device 251, Figs. 2 and 20, between the usual separable discs of which the needle-thread t is guided. It is desirable that the tension be released when the sewing mechanism is idle and to this end a lever 252 is fulcrumed at 253 to the bracketarm 3. The upper end of this lever is connected to a rod 254 slidably supported by the apertured post 255 and terminating in a wedge 256. The lower end of the lever 252 is connected by the link 257 to the stop-motion lever 177. When the stop-motion lever is in stopping or full line position, Fig. 2, the wedge 256 is projected between the tension discs 251, thus permitting the thread to run freely. When the stop-motion lever is tilted to start the stitch-forming mechanism, the wedge 256 is withdrawn from between the tension discs and the tension on the needlethread is restored.

The machine is preferably provided with suitable devices for safeguarding its operation, and to this end means are provided for forcibly restoring the finger starting-lever 164 to initial position, after it has been depressed to start the machine, and for look ing it in initial position until after the aux iliary shaft has substantiallv completed its second partial rotation. Mounted on the fulcrum screw 258, Figs. 2 and 6, is a bellcrank-lever one arm 259 of which extends inwardly to a position from which it may swing over and prevent elevation of the rearward end of the finger lever 164. The other arm 260 of the bellcrank-lever is held by a spring 261 in contact with a face cam 262 on the cam-cylinder 263 pinned to the auxiliary shaft 107. When the machine is stationary the follower arm 260 occupies the position in the depression 261 indicated in Fig. 28, and the lever-arm 259 is in unlocking or retracted position relative to the finger-lever 164, as shown in full lines, Fig. 17. lVhen the finger-lever is depressed to initiate the first partial rotation of the auxiliary shaft 107, the action of the inclined portion 163 of the cam-slot 160 in restoring the clutch-controlling lever to stopping position also causes the forcible restoration of the finger-lever to initial position by a pull on the rod 171. Before the offset 162 of the cam-slot 160 reaches the follower pin 161, however, the incline 261", Fig. 28, acts upon the follower arm 260 to swing the lever 259 to dotted line position, Fig 17, thereby locking the finger-lever 164 in initial position before the first partial rotation of the auxiliary shaft is completed. Interference with the proper automatic operation of the machine by accidental pressure on the finger-lever 164 is thus prevented.

Means are also provided for locking the clutch-controlling lever 152 against accidental displacement from stopping position while the sewing shaft 24 is running. Fulcrumed on the bracket 193 at 264 is a bell crank-lever the vertical arm 265 of which is forked toembrace the lateral screw-pin 266 on the link 195. The other arm 267, Fig. 6, of the bellcrank-lever terminates adjacent the inner end of a lateral extension 268 of the clutch-controlling lever 152. WVhen the stop-motion lever 177 is in stopping or full line position, Fig. 1, the end of the lever-' arm 267 is above the path of movement of the end of the extension 268 of the cluthcontrolling lever and does not block the movement of the latter to start the auxiliary shaft. When, however, the stop-motion lever 177 is in running position, the lever arm 267 occupies its dotted line position, Fig. 1, directly in the path of movement of the extension 268, thus locking the lever 152.

When the machine is stationary, the clutch-controlling lever extension 201 is resting upon the upper end of the lever-arm 207 as shown in Figs. 1, 4, 30 and 34. Depression of the finger-lever 164 swings the clutch-controlling lever to starting or dotted line position, Fig. 34; the pivoted lever extension 201 dropping from full to dotted line position, Figs. 4 and 30. As the auxiliary shaft 107 begins to make its first partial rotation, the cam rise 132 acts upon the lever-arm 202 to elevate the lever extension 201 to a position above the end of the lever-arm 207, as shown in Fig. 31. The

lever extension. 201 is similarly elevated by the cam 129 early in the second partial rotation of the auxiliary shaft, as shown in Fig. 33. The purpose of the cams 129 and 131-is to hold the lever extension '201 above the end of the arm 207 during the restoration of the clutch-controlling lever 152 to initial position by the inclined portions 163 of the cam-slot 160.

If the thread breaks during the action of the sewing mechanism, the operator may prevent the second partial rotation of the auxiliary shaft by manually elevating the pivoted lever extension 201 to dotted line position, Fig. 1, so that it will not be struck and shifted sidewise by the lever-arm 207 when the stop-motion plunger 176 lifts the lever-arm 209 at the end of the sewing operation. Pivoted at 269 to the lever 202, Fig. 1, is the link-bar 270 the forward end portion of which is formed with an L-shaped slot 271 entered by the supporting screw 272. The lever terminates in a finger-piece 273 and is formed with a vertical extension 274 terminating in a stop 275. Forward and downward pressure on the finger-piece 273 shifts the link-bar 270 to dotted line position, Figs. 1 and 6, thereby preventing the starting of the auxiliary shaft by the stopmotion plunger 176. The stop 275 locks the clutch-controlling lever 152 in stopping position and prevents accidental starting of the auxiliary shaft until the finger piece 273 is restored to initial position. If the first sewing is defective the operator can thus prevent the cutting of the buttonhole and the release of the work and can grasp the handle 177 on the stop-motion lever 177 and draw it forwardly, thereby restoring the stitchforming mechanism for a repetition of the sewing operation.

It is thought that the operation of the machine will be clear from the foregoing disclosure. It may be noted, however, that during the first partial rotation of the auxiliary shaft, the clamping-foot 44 is automatically lowered before the stitch-formin mechanism is started. During the second partial rotation of the auxiliary shaft, the threads are out before the clamping foot is elevated. While the control, in a buttonhole sewing machine, of the operations prior and subsequent to sewing by connections with a single rotary element or shaft having a plurality of partial rotations per buttonholeq'n'oducing cycle with intermediate intervals of rest, is considered to be the most important feature of the present improvement, it is to be understood that the invention embraces within its scope other features such as set forth in the appended claims.

Having thus set forth the nature of the invention. what I claim herein is- 1. In a buttonhole sewing machine, the combination with stitch-forming mechanism,

a work-holder, and means for relatively moving them to sew about a buttonhole, of an auxiliary rotary control element stationary during the sewing, a continuously rotating power element, a clutch connection between said elements for causing the rotary control element to turn with a continuous motion for a partial rotation prior to sewing and for a second partial rotation subsequent to sewing, each of said partial rotations being followed by a period of rest, devices auxiliary to the stitch-forming mechanism in the buttonhole producing cycle, and means driven by said rotary control element and connections for operating said devices.

2. in a buttonhole sewing machine, the combination with stitch-forming mechanism, a work-holder and means for relatively moving them to sew about a buttonhole, of an auxiliary rotary element stationary during the sewing, driving and stopping means for causing said rotary element to make a partial rotation prior to sewing the buttonhole and a second partial rotation subsequent to sewing, said rotary element making one complete rotation per complete cycle of operations of the machine, devices auxiliary to the stitch-forming mechanism in the buttonhole-producing cycle, and means driven by said rotary element and connections for operating said devices.

3. In a buttonhole sewing machine, the combination with stitch-forming mechanism, a work-holder, and means for relatively moving them to sew about a buttonhole, of an auxiliary rotary control element stationary during the sewing, a power element rotating continuously at a constant speed and arranged coaxially with said rotary control element, a clutch connection between said elements for causing the rotary control element to turn with a continuous motion at the speed of the power element for a partial rotation prior to sewing and for a second partial rotation subsequent to sewing, each of said partial rotations being followed by a period of rest, devices auxiliary to the stitch-forming mechanism in the buttonhole producing cycle, and means driven by said rotary control element and connections for operating said devices.

4. In a buttonhole sewing machine, the combination with stitch-forming mechanism including a sewing shaft, a work-holder, and means for relatively moving the stitch-forming mechanism and work-holder to sew about a buttonhole, of an auxiliary shaft, a constantly rotating driving element journaled loosely on said auxiliary shaft, means for coupling said auxiliary shaft to said driving element for a partial rotation of the latter prior to sewing, and for again coupling said shaft to said element fora second partial rotation subsequent to sewing, each shaft being followed by a period of rest,

devices auxiliary to the stitch-forming mechanism in the complete cycle of the machine, and means driven by said rotary shaft and connections for operating said devices.

5. In a buttonhole sewing machine, in combination, a frame comprlsin a bed, a standard rising from one end 0 said bed. and a bracket-arm carried by said standard and overhanging said bed, stitch-forming mechanism incorporated in said frame, a work-holder, means for relatively moving the stitch-forming mechanism and workholder to. sew about a buttonhole, an auxiliary shaft journaled transversely of the machine bed and stationary during the sewing, driving and stopping means for causing said shaft to make a partial rotation with a continuous motion prior to sewing and a second partial rotation with a continuous motion subsequent to sewing, said shaft making one complete rotation automatically per buttonhole-producing cycle, devices auxiliary to the stitch-forming mechanism in the buttonhole-producing cycle, and means carried by said auxiliary shaft and connections for operating said devices.

6. In a buttonhole sewing machine, in combination, stitch-forming mechanism, a work-holder means for relatively moving the stitch-forming mechanism and workholder to sew about a buttonhole, a stop-motion device for controlling the period of operation of the stitch-forming mechanism, an auxiliary rotary control element stationary during the sewing, driving and stopping means for causing the auxiliary element to make a partial rotation with a continuous motion prior to sewing and a second partial rotation with a continuous motion subsequent to sewing, each of said partial rotatlons being followed by .a period of rest, means actuated by said control element during its first partial rotation for operating the stop-motion device to start the stitchformin mechanism, a buttonhole slit-cutter, and means on said control element and connections for operating said slit-cutter.

7. In a sewing machine, in combination, stitch-forming mechanism, a work-holder, means for relatively moving the stitchforming mechanism and work-holder to sew a group of stitches, a stop-motion device for controlling the period of operation of the stitch-forming mechanism, an auxiliary rotary element stationary duringthe sewing, driving and controlling means for causing the auxiliary element to make a partial rotation with a continuous motion prior to sewing and a second partial rotation with a continuous motion subsequent to sewing, each of said partial rotations being followed by a period of rest, a work-holder closing device, a needle-thread-cutter, and means carried by said auxiliary element and connections for closing the work-holder, operating the stop-motion device to start the stitch-forming mechanism and for operating the needle-thread-cutter subsequent to the sewing operation.

8. In an automatic buttonhole sewing machine, in combination, stitch-forming mechanism, a work-holder, means for relatively moving the stitch-forming mechanism and work-holder to sew about a buttonhole, a stop-motion device for controlling the period of operation of the stitch-forming mechanism, an auxiliary rotary element stationalry during the sewing, driving and controlling means for causing said auxiliary element to make a partial rotation with a continuous motion prior to sewing and a second partial rotation with a continuous motion subsequent to sewing, each of said partial rotations being followed by a period of rest, a buttonhole slit cutting device, and means on said auxiliary element and connections for operating said buttonhole slit cutting device.

9. In a buttonhole sewing machine, in combination, stitch-forming mechanism, a sewing shaft and connections for operating the stitch-forming mechanism, a workholder, means for relatively moving the stitch-forming mechanism and work-holder to sew about a buttonhole, an auxiliary rotary element stationary during the sewing, driving and stopping means for causing said element to make a part only of a complete rotation prior to sewing the buttonhole and the remaining part of such coinplete rotation after the buttonhole has been sewed, each of said partial rotations being followed by a period of rest, and means on said element and connections for effecting the opening and closing of the work-holder.

10. In a sewing machine, in combination, stitch-forming mechanism, a stop-motion therefor, a work-holder, means for relatively moving the stitch-forming mechanism and work-holder to sew a group of stitches, an

auxiliary rotary element stationary during the sewing, means for causing said element to make a partial rotation with a continuous motion prior to sewing and a second partial rotation with a continuous motion subsequent to sewing, each of said partial rotations being followed by a period of rest. means on said auxiliary element, and connections for opening and closing the Workholder, and means actuated by said auxiliary element during its first partial rotation for operating the stop-motion to start the stitch-forming mechanism.

11, In a buttonhole sewing machine, in combination, stitch-forming mechanism, a work-holder, means for relatively moving the stitch-forming mechanism and work- 

